Alternatively, your forward thinking company could produce an App that allows you to stick the temperature, QNH AND the altitudes and produce a set of corrected altitudes in seconds. Or a rough and ready table on the winter ops guide. I have worked for airlines that have done both.
It really is isn't difficult. It takes 5 minutes away from reading the paper in the cruise. Checking your vertical profile in IMC is a business of life or death. With the switchover to paperless flight decks it surely can't be long before LIDO, Jepp, Navtech insert a function into their approach plates for you to enter the QNH and temperature and automatically display the correct crossing altitudes.